From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: BUG: unable to handle kernel NULL pointer dereference at 000000000000002c Date: Thu, 01 Dec 2011 21:20:44 +0100 Message-ID: <1322770844.2750.1.camel@edumazet-laptop> References: <4ED7C367.3070109@profihost.ag> <20111201182309.GA10686@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Stefan Priebe , netdev@vger.kernel.org, Dave Chinner , stable@vger.kernel.org To: Christoph Hellwig Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:56486 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753453Ab1LAUUu (ORCPT ); Thu, 1 Dec 2011 15:20:50 -0500 In-Reply-To: <20111201182309.GA10686@infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: Le jeudi 01 d=C3=A9cembre 2011 =C3=A0 13:23 -0500, Christoph Hellwig a = =C3=A9crit : > On Thu, Dec 01, 2011 at 07:11:51PM +0100, Stefan Priebe wrote: > > Hi, > >=20 > > i'm not quite sure if this is an XFS thing or a tcp thing. As the > > stacktrace confuses me a little but as it contains > > xfs_bmap_search_extents and xfs_iunlock. Kernel is 3.0.11 running a= s > > 2.6.40.11. > >=20 > > [171464.091567] BUG: unable to handle kernel NULL pointer > > dereference at 000000000000002c > > [171464.092073] IP: [] ipv4_dst_check+0xb6/0x190 > > [171464.092073] PGD 15344e067 PUD 14c821067 PMD 0 > > [171464.092073] Oops: 0002 [#1] SMP > >=20 > > Full Stacktrace: > > http://pastebin.com/raw.php?i=3DQNg6jD2t >=20 > The ? entries mean even the backtrace code things they are unreliable= , > and mos of the cases I've seen they are wrong. In this case it looks > like the process was doing XFS work before, but the current system ca= ll > indeed is purely in the networking code. >=20 > I've changed the cc list to the netdev list which is more appropinqua= te. Probably fixed by commit 81d54ec8479a2c695760da (net: fix NULL dereferences in check_peer_redir()) But this patch needs some followup patches (some of them in David net tree, not yet in Linus tree)